Introspection on vsc.randobj

[msmftc]

@mballance,

In my application I need some introspection on classes that are decorated with @vsc.randoj. Given a reference to such a class, I need to determine the module that the class was defined in. The class property __module__ typically has this information, but decorating the class changes __module__ to vsc.rand_obj

Based on advice I found on the internet, I tried adding a @functools.wraps decorator inside the function vsc.randobj(), but that did not help. The only solution that I've found is to add a new line of code to vsc.randobj() that stores the original module name in a new property, as shown here:

def randobj(*args, **kwargs):
    if len(args) == 1 and len(kwargs) == 0 and callable(args[0]):
        # Called without arguments
        obj = _randobj({})
        args[0].original_module = args[0].__module__  # NEW LINE OF CODE
        return obj(args[0])
    else:
        obj = _randobj(kwargs)
        return obj

This lets me read the original module name, as shown in the example below, but I'd rather not use a hacked version of PyVSC. Do you know how I can read the original module using the current PyVSC code? If not, then can you think of a simple PyVSC change that would permit introspection of decorated classes?

In this example, the original module name is __main__ for both HelloClass and Selector:

import vsc

class HelloClass:
    string = "Hello"

@vsc.randobj
class Selector:
    def __init__(self):
        self.a = vsc.rand_uint16_t()


print(f"HelloClass Module =          {HelloClass.__module__}")
print(f"Selector Module =            {Selector.__module__}")
print(f"Selector original_module =   {Selector.original_module}")

HelloClass Module =          __main__
Selector Module =            vsc.rand_obj
Selector original_module =   __main__

[mballance]

@msmftc, thanks for raising this. In general, the goal of vsc.randobj is to be transparent. Certainly, it adds some functions and behavior to a user class, but it is intended to (largely) leave the user's view of the class undisturbed. The example you show about highlights a situation where this isn't the case.
Let me give this a bit more thought, but my initial reaction is that the vsc.randobj decorator should propagate attributes such as __module__ back to the new class defined by vsc.randobj. My biggest concern is what attributes, beyond __module__, will be overlooked and need to be added incrementally...

[mballance]

Note: this has been addressed in the 0.8.1 release